The Sentinels are a series of large humanoid robots designed to combat various mutant threats.
When Sentinel Prowlers proved ineffective against the more dangerous mutants as well as groups of mutants, the Mutant Response Division created larger humanoid machines. They were more durable and could deal more damage. They were designed by Bolivar Trask and Dr. Sybil Zane. The Sentinels were controlled by the computer program Master Mold.
At one point, Senator Robert Kelly sent a group of Sentinels to Genosha to destroy Magneto. He took control of the robots and tried to take over humanity. The X-Men stopped them both making them see the error of their ways.
Alternate Version Edit
In a dystopian future, the Sentinels took over the planet exterminating most of the population. Sentinel Prowlerswere still around as well as the Sentinel Hounds, which were based on Wolverine's powers. These versions were erased when Charles Xavier warned the X-Men and got them to prevent this disaster.